Due to the maximum physical size constraints of airborne weather radar antennas, a desired narrow antenna beam is often not achieved, thus resulting in less-than-desired detail in displayed weather data. This is especially evident in vertical displays (relatively new to the industry) and is worse with smaller antennas (e.g., those used in business jets).
Well-known Doppler beam-sharpening techniques will not work well straight ahead of the aircraft or in the vertical direction. Also, the natural Doppler noise of weather might be another challenge.
Small aircraft can fit only small, wide-beam antennas, thus limiting their beam-sharpening abilities.
FIGS. 1 and 2 show some problems evident on a vertical display because of 15:1 expansion of vertical scale. The problems are as follows:                low resolution, due to antenna beam width;        blocky appearance, due to quantization of volumetric data; and        attempts to smooth output for display result in a tradeoff between smoothness and further resolution loss.        
A straightforward approach of converting to frequency domain and multiplying by an inverse of the beam pattern (either real or a “softened” notional antenna) fails to work with real data because it involves dividing by very small numbers and thus the data became unstable.